Author(s): MAUFRAIS, C., JOSSE, M., PATRIER, L., ISNARD, M., GRANDPERRIN, A., TURC-BARON, C., NOTTIN, S., CRISTOL, J.P., OBERT, P., Institution: AVIGNON UNIVERSITY, Country: FRANCE, Abstract-ID: 727

INTRODUCTION:
Cardiovascular diseases are present in more than 50% of patients with End-Stage Kidney Disease (ESKD). Hemodialysis (HD) is a life-saving treatment but it also induces LV regional wall motion abnormalities (RWMAs) that leads to LV systolic dysfunction due to a transient myocardial ischemia, a phenomenon well-known as myocardial stunning. Such repetitive ischemic insults are widely recognized to be important in the pathogenesis of cardiac failure and contribute to the excess cardiovascular mortality in this population. Therapeutic strategies to mitigate cardiovascular disorders associated with HD are therefore mandatory. Acute intradialytic exercise (IDE) has the exciting potential to be cardioprotective in patients with ESKD. However, studies analyzing its effect on myocardial stunning are scarce, and include a small number of patients and some methodological bias. We aimed to explore 1) the impact of IDE on the regional occurrence of RWMAs in a large cohort of exercise-naïve subjects receiving HD and 2) the benefits of the cardioprotection induced by IDE according to the clinical characteristics of patients.
METHODS:
In this prospective, open-label, two-center randomized crossover trial, 72 stable patients performed 2 HD sessions in a random order: a standard HD (HD-CONT) and a session incorporating 30min of aerobic exercise (HD-EX). Echocardiography was performed immediately before HD (T0) and at peak stress of HD (i.e. 30 min before HD ending, Tpeak) during each session. An 18-segment model was used to identify RWMAs, defined as a 20% reduction in longitudinal strain at Tpeak compared to T0. Myocardial stunning was confirmed for patients who developed at least 2 RWMAs at Tpeak.
RESULTS:
IDE significantly reduced the number of RWMAs during HD-EX compared to HD-CONT (estimated difference: 1.1segment, 95%CI: 0.33/1.90, p=0.009). There was a base-to-apex benefits gradient of IDE with the greatest reduction in RWMAs observed at the apex during HD-EX when compared to HD-CONT. Overweight patients had a decrease in RWMAs during HD-EX compared to HD-CONT (HD-CONT: 7.1±3segments, HD-EX: 5.3±3segments; p<0.001) whereas we observed no significant difference for normoponderal patients (HD-CONT: 6.5±3.5segments, HD-EX: 6.2±3.5segments; p=0.99).
CONCLUSION:
We confirm that IDE limits the myocardial stunning induced by HD. Using a regional analysis for the first time in the literature, we exposed a reduction in the number of RWMAs occurring during HD-EX compared to a standard session with greater benefits observed at the apical level. The most relevant clinical characteristic related to the decreased myocardial stunning induced by IDE was the ponderal status of patients. Overweight individuals presented a greater decrease in RWMAs compared to normoponderal patients.
Further studies are needed to fully elucidate the mechanisms underlying the benefits of IDE on the regional myocardial function and better identify the clinical factors that determine the degree of cardioprotection.